Childhood Antisocial Behavior and Adolescent Alcohol Use Disorders

Antisocial behaviors (e.g., aggression toward people and animals, destruction of property, deceitfulness, theft, and serious rule violations) and related mental disorders (i.e., conduct disorder and oppositional defiant disorder) during childhood predict alcohol use disorders (AUDs) during adolescence. This sequence of disorders may reflect developmentally specific forms of deficits in the ability to control behavior. Therefore, childhood antisocial behaviors and adolescent AUDs may share common genetic and environmental influences. A comprehensive conceptual model may clarify the relationship between childhood antisocial behaviors and adolescent AUDs. A better understanding of this relationship is essential for advancing research into the causes of both behaviors and for developing prevention programs and treatment for adolescents with these problems. Prevention programs targeting childhood antisocial behaviors have met with some success. Clinical interventions for adolescents with AUDs may be improved by focusing evaluation and treatment planning on antisocial behavior.

C hildhood antisocial behaviors are a central element in the developmental pathway leading to adolescent alcohol abuse or depen dence. Theories and empirical observa tions indicate that childhood antisocial behaviors increase the risk for alcohol use disorders (AUDs). In its most severe forms, childhood antisocial behavior can lead to diagnoses of conduct disorder (CD) or oppositional defiant disorder (ODD). Particularly for children meet ing the criteria for CD, childhood antisocial behaviors predict early initiation of alcohol use, adolescent alcohol-related problems, and the onset of AUDs (Cadoret et al. 1995;Clark et al. 1998aClark et al. , 1999. (Throughout this review, the term "childhood" will refer to age 12 and younger, and "adolescence" will refer to ages 13 through 18.) Understanding the nature of the relationship between antisocial behaviors and AUDs is essen tial in planning interventions designed to prevent or ameliorate both types of behaviors or disorders.
This article reviews antisocial behav iors and related mental disorders com monly found in children and adolescents and describes the relationship between antisocial behaviors and alcohol problems. The article then presents a conceptual model for explaining this relationship, including genetic and environmental factors that may play a role in the pro cess. Finally, the article summarizes the implications of the relationship between antisocial behaviors and AUDs for understanding the etiology of AUDs, for developing effective methods to prevent alcohol problems, and for evaluat ing and treating adolescents with AUDs.
illegal behavior, and defiance of generally accepted rules and authority, such as truancy from school. These antisocial behaviors exist along a severity continuum. When childhood antisocial behaviors exceed certain defined thresholdsthe diagnostic criteria specified in the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV) (American Psychiatric Association 1994)-the child is consid ered to have CD or ODD. Together with attention deficit hyperactivity dis order (ADHD), these two disorders are classified as "disruptive behavior disor ders" in the DSM-IV.

Conduct Disorder (CD).
Antisocial behaviors represented in the DSM-IV diagnostic criteria for CD include aggression toward people and animals, destruction of property, deceitfulness, theft, and other serious social rule vio lations (see textbox, below). A diagnosis of CD also requires a persistent behav ior pattern in which 3 or more of a total of 15 behaviors occur over a 12month period. The DSM-IV specifies childhood-onset and adolescent-onset types of CD and different degrees of severity of the disorder.

Oppositional Defiant Disorder (ODD).
ODD is characterized by negativistic, hostile, and defiant behaviors, such as losing one's temper, arguing, defying DUNCAN B. CLARK, M.D., PH.D., and JACK CORNELIUS, M.D., M.P.H.,  rules, deliberately annoying others, blaming others for one's behavior, and displaying anger or vindictiveness (see textbox, p. 111). In addition, a diagno sis of ODD according to the DSM-IV criteria requires a pattern of behavior lasting at least 6 months in which 4 or more of a total of 8 behaviors are exhib ited. A diagnosis of CD supercedes ODD-that is, if a child meets the cri teria for both CD and ODD, he or she will be diagnosed with CD.

Dimensions of Antisocial Behavior
Diagnoses summarize a constellation of characteristics as the presence or absence of a disorder. Although diagnostic clas sifications of such antisocial behaviors as CD and ODD have both practical and scientific utility, one can also con ceptualize these behaviors as occurring along multiple dimensions. Relevant dimensions include the categories of behaviors required for a diagnosis of CD, such as aggression and deceitful ness. One can also distinguish between overt antisocial behaviors, such as fight ing, and covert antisocial behaviors, such as theft without confronting the victim (Loeber et al. 2000). The extent to which such dimensions correspond to the diagnostic classifications specified in DSM-IV is a matter of some debate. On the one hand, the available empirical literature indicates that the DSM-IV distinction between ODD and CD is clinically useful for children in general (Loeber et al. 2000) and for adolescents with AUDs in particular (Moss and Lynch 2001). On the other hand, these syndromes are multidimensional, and some features overlap between CD and ODD (i.e., are diagnostically ambiguous) (Hartman et al. 2001). For CD, overt antisocial behaviors may be meaningfully distinguished from covert antiso cial behaviors (Loeber et al. 2000).
Developmental considerations are also important for understanding the

Diagnostic Criteria for Conduct Disorder
Conduct disorder is diagnosed if a persistent pattern of behavior involving three or more of the following behaviors is present over a 12-month period.

Diagnostic Criteria for Oppositional Defiant Disorder
Oppositional defiant disorder is diagnosed if a pattern of behavior involving four or more of these criteria is present for at least 6 months.
• Often loses temper • Often argues with adults • Often actively defies or refuses to comply with adults' requests or rules • Often deliberately annoys people • Often blames others for his or her mistakes or behavior • Is often touchy or easily annoyed by others • Is often angry or resentful • Is often spiteful or vindictive (American implications of particular antisocial behaviors for predicting outcomes. For example, the early emergence of aggres sive behaviors tends to be accompanied by ODD (Loeber et al. 2000) and to predict later CD (Côté et al. 2001).

Developmental Continuity and Specificity
Serious antisocial behaviors, including severe forms of ODD and CD, have remarkable developmental stability in boys and girls-that is, these behaviors persist throughout various stages of childhood and adolescence. Mild or moderate forms of the disorders, however, are considerably less stable (Loeber et al. 2000). Antisocial behaviors also tend to be consistent across social settings, such as school and home (Dishion et al. 1995). Although the propensity for serious antisocial behaviors is quite sta ble across the lifespan, the manifesta tions of this propensity vary according to developmental stages. This concept has been termed "heterotypic continuity" (Moffitt 1993). For example, antisocial behavior that manifests as irritability and impulsivity in young children may manifest as criminal behavior once these children reach adulthood.
The significance of specific childhood antisocial behaviors also depends, in part, on the timing of their appearance. For example, CD that develops early in life is often preceded by ODD (Loeber et al. 2000), suggesting that ODD behaviors that develop early can predict early onset CD. An earlier age of onset of CD has been hypothesized to indicate more severe antisocial characteristics, although to date empirical support for this hypothesis exists only for boys (Loeber et al. 2000).
The extent to which antisocial behav iors persist across multiple developmen tal periods also may be an important distinguishing feature (Moffitt 1993). For example, in some people such behaviors occur during childhood, ado lescence, and adulthood (i.e., are "lifecourse persistent"), whereas in other people they are evident only in one developmental stage. This developmental distinction may be useful in understand ing the relationship between antisocial behavior and AUDs. Correlations among various antisocial behaviors over time have led to the theory that a general tendency toward psychological dysreg ulation may underlie many forms of childhood and adolescent psychopathol ogy, including alcohol and other drug use disorders (Tarter et al. 1999).

Antisocial Behaviors Predict Alcohol Problems
Prospective, longitudinal studies (i.e., studies that followed participants over several years) of children who initially did not exhibit behavior problems have provided clear evidence that childhood antisocial behaviors predict adolescent alcohol involvement and AUDs. Thus, childhood manifestations of deficits in the ability to control behavior (i.e., behavioral undercontrol), including CD and ODD, predict the initiation of regular alcohol use in early adoles cence (Clark et al. 1998a) and the onset of alcohol-related problems (Clark et al. 1999) and AUDs (Caspi et al. 1996;Rydelius 1981) during adoles cence. ADHD may be less relevant because it did not predict AUDs in some studies (Mannuzza et al. 1998). In other studies, ADHD did predict adolescent alcohol and drug problems; however, that association may have been attributable to CD co-occurring in the children with ADHD (Clark et al. 1999). Finally, children of parents with alcohol and other drug use disorders (i.e., high-risk children) have increased rates of antisocial behaviors. Childhood antisocial behavior, such as noncompli ance with parental directives in the tod dler years (Eiden et al. 2001), and CD and ODD in the school-age years (Clark et al. 1997a) are more common in chil dren at high risk for alcohol and other drug use disorders.
Based on these observations, it is clear that childhood antisocial behavior precedes and predicts adolescent AUDs. Consequently, a conceptual model is needed to guide further investigation into the causal relationships between both types of behaviors. Such a model is presented in the following section.

A Conceptual Model
Conceptual approaches from several traditions have proven useful for devel oping theories about the relationship between childhood antisocial behaviors and adolescent AUDs. The model pre sented here, and described in more detail in Clark and Winters (in press), represents an integrated conceptual model and measurement approach that allows researchers to consider the mul tiple causes and effects shaping this relationship. This model is informed by prior theories (Zucker et al. 1995;Tarter et al. 1999), assessment method ologies (Clark et al. 2001), and research (Clark et al. 1999) in this area. The model combines two approaches:

• The multifactorial model of complex traits.
This model assumes that individual differences in observable characteristicsin this case, antisocial behaviors and AUDs-are determined by variations in the combined influences of multi ple genes and environmental factors (Lander and Schork 1994;Vanyukov and Tarter 2000).
• The theoretical framework of developmen tal psychopathology. This framework emphasizes specific methodological approaches and conceptual issues by contrasting normal and atypical devel opment. It also takes into consideration that the effects of risk factors may vary across developmental stages (Cicchetti and Cohen 1995).
This model, as well as conceptual izations from several other traditions, hypothesizes that childhood antisocial behaviors and adolescent AUD have common causes. Several mechanisms may underlie these common causes. First, both antisocial behaviors and AUDs may be manifestations of a fundamental deficiency in the person's ability to control or regulate his or her behavior (Tarter et al. 1999). Second, the observed relationship between antisocial behaviors and AUDs may reflect the presence of common genetic factors and/or environmental influences. These mechanisms, which are not mutually exclusive and can both be included within the proposed comprehensive model, are discussed in more detail in the following sections.

The Dysregulation Hypothesis
A common underlying factor-namely, a tendency toward poor behavioral reg ulation-may predispose some people to both childhood antisocial behaviors and AUDs (Cadoret et al. 1995). Behavioral undercontrol (also referred to as "behavioral dysregulation" and "disinhibition") is characterized by deficits in the planning and execution of goaldirected behavior, and is manifested by aggressive, antisocial, and impulsive behavior (Martin et al. 2000), all of which predict problematic alcohol use (Caspi et al. 1996). Behavioral under-control also has been hypothesized to underlie the observed associations among childhood CD, alcohol and other drug use disorders, and adult antisocial per sonality disorders.
During a person's development, the ability to regulate and control behaviors and emotions emerges at the same time that a brain region called the prefrontal cortex matures. Accordingly, researchers have hypothesized that the neurobio logical functions that modulate thoughts (i.e., cognition), the emotions associated with those thoughts (i.e., affect), and behavior are located in the prefrontal cortex (Spear 2000). Consistent with this hypothesis, neuroimaging findings indicate that abnormalities in the struc ture of the prefrontal cortex are associated with severe antisocial behavior (Raine et al. 2000). The rate with which certain brain circuits involving the prefrontal cortex mature may be an important mechanism through which genetic factors influence psychopathological manifestations (Todd et al. 1995).

Genetic Influences
Behavior Genetics. Researchers have begun to investigate the extent to which similarities in antisocial behavior and AUDs among relatives result from genetic inheritance (i.e., shared genes) or envi ronmental factors. Studies in this area have provided convincing evidence that genetic factors contribute substantially to individual variations in both antiso cial behavior and AUDs (Tarter et al. 1999). Some studies have also suggested that the high correlations between ODD and CD symptoms can be attributed to genetic similarity (Eaves et al. 2000). The characteristic features of behavioral undercontrol are highly susceptible to genetic influence, and common genetic factors may account for the associations between antisocial behaviors and drug use (Young et al. 2000). To explore the role of genetic factors in the intergener ational transmission of antisocial behav ior, Cadoret and colleagues (1995) studied adopted children and their biolog ical and adoptive parents. They found evidence for a genetically transmitted pathway leading from antisocial per sonality disorder and drug use disorders in the biological parent to CD in the offspring and, subsequently, drug use disorders and antisocial personality dis order in the offspring.
Other studies found that the corre lation between childhood antisocial behavior and adult drug use disorders is more strongly influenced by genetic factors than is the correlation between adult antisocial behaviors and drug use disorders (Grove et al. 1990). This observation reinforces the notion that childhood characteristics are of funda mental importance for the development of adult behaviors. The relationship between childhood antisocial behavior and the later development of AUDs may be the result of common genetic influences (Waldman and Slutske 2000).

Molecular Genetics.
In general, varia tions in the structure of certain genes (i.e., genetic polymorphisms) account for the inheritance of individual differ ences in behavior. Although extensive evidence has established that heritable factors are a major influence in the devel opment of AUDs, researchers have not yet been able to identify the mechanisms leading to the development of AUDs and the specific genes involved. One candidate that has been implicated in AUDs is a brain signaling system called the dopamine neurotransmitter system. Individual differences in this system are likely to influence the extent to which a person experiences alcohol's effects as pleasant and therefore wants to consume more alcohol (i.e., the extent to which a person experiences drinking as posi tively reinforcing). Variations in the level of reinforcement obviously can influence a person's risk for alcohol and other drug use disorders. Accordingly, researchers have begun to study associ ations between genetic polymorphisms influencing dopamine and other brain signaling systems on the one hand, and the risk for AUDs on the other hand (Vanyukov and Tarter 2000). These associations may provide insights into the genetic, biochemical, and neurobi ological mechanisms underlying AUDs and may also reveal the nature of the relationship between AUDs and antiso cial behaviors .

Environmental Influences
Several environmental factors have been found to increase the risk for antisocial behavior as well as AUDs in adolescents. These influences include problematic family functioning, such as low levels of parental monitoring and inconsistent disciplinary practices (Clark et al. 1998b), as well as childhood maltreatment (Clark et al. 1997b). The developmental psychopathology framework described earlier suggests that specific environmental factors may be particularly influential during critical developmental periods. For example, paternal drug use disorders may have differential effects depending on a child's stage of development. In a study exam ining psychopathology in a sample of high-risk boys (Moss et al. 1997), boys whose fathers overcame drug use disorders prior to the child's school-age period were similar to a control group of boys whose fathers had no drug use disorders. Conversely, boys whose fathers had continuing drug use disorders exhibited significant psychopathology.
Parents' drug use and other pathology may affect the development of their offspring through several mechanisms. For example, parental drug use and other pathology may directly influence parent ing behaviors. In addition, the effects of parental pathology may be indirect. Thus, parental mental disorders may act as barriers impeding their children's access to adequate mental health treat ment, which in turn may increase the children's likelihood of developing AUDs in adolescence (Cornelius et al. 2001).
Environmental influences invariably interact with genetic factors to determine a person's risk for certain disorders. The dynamic interaction of genetic and environmental influences with certain behaviors over the course of development is particularly complex and therefore difficult to analyze (Tarter et al. 1999). For example, for AUDs to develop, alcohol availability in the environment (e.g., from family or friends) is a neces sary but not sufficient condition. An adolescent who chooses peers who use alcohol and other drugs may be more frequently exposed to alcohol than is an adolescent with a different peer group. When combined with a genetic predisposition to alcohol dependence, the adolescent's selection of deviant peers and consequent high exposure to alcohol may result in the development of AUDs. Such interactions are ideally taken into consideration when study ing the relationship between childhood antisocial behaviors and AUDs.

Implications for Prevention, Evaluation, and Treatment
A causal model explaining the association between childhood antisocial behaviors and the development of AUDs during adolescence, if it can be validated, has implications for the prevention, evalua tion, and treatment of those behaviors. For example, early intervention for antisocial behaviors might reduce the risk of developing an AUD, and treatment for AUDs might be more effective if it also addressed behavioral undercontrol. These possible implications are reviewed in the following sections.

Prevention
A potentially effective strategy to prevent the development of AUDs involves using interventions designed to reduce childhood characteristics that predict adolescent AUDs, such as childhood antisocial behavior. Several research programs have been investigating this approach, and early reports have shown promising results. For example, Linking the Interests of Family and Teachers (LIFT) is an elementary-school preven tion program that uses behavior modifica tion with children on the playground, provides social and problem-solving skills training to children in the classroom, and offers parenting skills train ing to their parents (Eddy et al. 2000). When the children receiving the LIFT intervention and a group of control children were reevaluated 3 years after the intervention, the LIFT program was found to delay the time to first regular alcohol use, first marijuana use, and first police arrest. Other similar projects are in progress (e.g., Ialongo et al. 2001). Researchers also have identified effec tive interventions for childhood CD (Sheldrick et al. 2001), which may reduce the risk for adolescent AUDs.

Evaluation
A comprehensive assessment, including a systematic evaluation of the patient's history of antisocial behaviors and drug use disorders, is the foundation for effective treatment planning for adoles cents with these problems. Too often, clinical assessments lack this foundation. For example, clinical assessment strate gies are typically unstructured and may lead to inaccurate diagnoses (Clark et al. 1995). Systematic diagnostic interviews provide for a more thorough assessment with greater reliability and validity and have been advocated for both clinical evaluations and research (Clark et al. 1999). Moreover, additional domains should be included in such comprehensive assessments, including parent-adolescent relationships, peer characteristics, school functioning, and health. Clark and Winters (in press) have proposed assess ment strategies that are designed to provide the comprehensive and devel opmentally appropriate information that is necessary for clinical interventions, prevention, and related research.
It is also important to recognize that AUDs have risk factors and consequences that manifest differently at various developmental stages. Assessment of relationships among various behaviors over time requires specialized measure ment approaches called "diachronic assessment" strategies (Clark et al. 2001).
Recently developed statistical techniques that can provide more realistic summaries of growth and development (e.g., Muthén and Muthén 2000) allow optimal sta tistical modeling of data obtained with such assessment approaches. The use of diachronic assessment strategies in combination with such innovative sta tistical modeling techniques can allow insights into the relationships among problem behaviors such as antisocial behavior and AUDs.
for patients with AUDs, adolescents participating in conventional alcoholism treatments have high relapse rates (Cornelius et al. in press). Several clinical studies have indicated that co-occurring CD predicts particularly poor outcomes among adolescents receiving treatment for alcohol and other drug problems (Brown et al. 1996;Crowley et al. 1998;Kaminer et al. 1992). Accordingly, programs for adolescents with AUDs may need to include interventions designed to reduce antisocial behaviors.
Several treatment approaches specif ically target CD. Psychosocial interven tions with standardized methods and documented effectiveness include train ing parents in child management tech niques and teaching children prosocial responses to interpersonal conflicts (Sheldrick et al. 2001). Stimulant med ications, such as methylphenidate (Ritalin ® ) may also improve CD (Klein et al. 1997). The extent to which such psychosocial and pharmacological treatments for CD also improve the outcome of adolescents with coexisting CD and AUDs requires further research.
For patients with co-occurring antisocial behaviors and AUDs, behavioral treatments may be more effective when the interventions target multiple domains, including the individual, family, and peers. Interventions using this strategy, such as the Multisystemic Treatment approach, have been shown to improve outcome compared with less intensive approaches. For example, in a clinical adolescent sample, the Multisystemic Treatment approach reduced both drug use and antisocial behavior (Henggeler et al. 1998).

Future Directions
Although researchers and clinicians have long recognized the relationship between childhood antisocial behavior and adolescent AUDs, a need remains for further research into the mechanisms underlying this relationship, as well as for prevention and treatment research. For example, treatment studies need to define the cost-effectiveness of inter ventions and determine how treatment gains made in supervised settings (i.e., clinical studies) can be transferred to real-life settings (e.g., home and school). Moreover, the potential benefits of simultaneously treating antisocial behav ior and AUDs must be elucidated fur ther. Future studies also must consider gender differences more thoroughly, because although antisocial behaviors and AUDs are more common in males, females with these characteristics may have more problematic outcomes (Loeber et al. 2000). Finally, as researchers more clearly identify the genetic and environ mental influences on childhood antiso cial behaviors and adolescent AUDs, they also need to further examine the effects of environmental influences on the persistence of these behaviors.
Treatment programs simultaneously addressing multiple domains represent an ideal and necessary approach for some adolescents with AUDs. The high costs of such comprehensive programs, however, limit their application. Furthermore, many adolescents with AUDs may have acceptable outcomes with conventional, less intensive interven tions (Maisto et al. 2001). Therefore, researchers and clinicians must develop more extensive empirical data to serve as a basis for making specific treatment recommendations in order to increase the likelihood that policymakers and payers (e.g., insurance companies) accept the increased costs associated with more comprehensive services. And although the cost of providing intensive interven tions for adolescents with AUDs is con siderable, the societal cost of neglecting these highly problematic adolescents is even greater (Scott et al. 2001).
Substantial challenges remain in understanding the relationship between childhood antisocial behavior and ado lescent AUDs. Both antisocial behav iors and AUDs are complex problems with multiple contributing factors. Consequently, genetic, family, epidemi ological, and clinical studies are needed to define clinically meaningful patient subgroups, identify children at highest risk for AUDs, and inform more effective prevention and treatment efforts. s